Classifications

• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
  • H01F7/00—Magnets
  • H01F7/06—Electromagnets; Actuators including electromagnets
  • H01F7/08—Electromagnets; Actuators including electromagnets with armatures
  • H01F7/16—Rectilinearly-movable armatures
  • H01F7/1607—Armatures entering the winding
• • G—PHYSICS
  • G05—CONTROLLING; REGULATING
  • G05D—SYSTEMS FOR CONTROLLING OR REGULATING NON-ELECTRIC VARIABLES
  • G05D16/00—Control of fluid pressure
  • G05D16/20—Control of fluid pressure characterised by the use of electric means
  • G05D16/2006—Control of fluid pressure characterised by the use of electric means with direct action of electric energy on controlling means
  • G05D16/2013—Control of fluid pressure characterised by the use of electric means with direct action of electric energy on controlling means using throttling means as controlling means
  • G05D16/2024—Control of fluid pressure characterised by the use of electric means with direct action of electric energy on controlling means using throttling means as controlling means the throttling means being a multiple-way valve
• • G—PHYSICS
  • G05—CONTROLLING; REGULATING
  • G05D—SYSTEMS FOR CONTROLLING OR REGULATING NON-ELECTRIC VARIABLES
  • G05D16/00—Control of fluid pressure
  • G05D16/20—Control of fluid pressure characterised by the use of electric means
  • G05D16/2093—Control of fluid pressure characterised by the use of electric means with combination of electric and non-electric auxiliary power
  • G05D16/2097—Control of fluid pressure characterised by the use of electric means with combination of electric and non-electric auxiliary power using pistons within the main valve
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
  • H01F7/00—Magnets
  • H01F7/06—Electromagnets; Actuators including electromagnets
  • H01F7/08—Electromagnets; Actuators including electromagnets with armatures
  • H01F7/13—Electromagnets; Actuators including electromagnets with armatures characterised by pulling-force characteristics
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16H—GEARING
  • F16H61/00—Control functions within control units of change-speed- or reversing-gearings for conveying rotary motion ; Control of exclusively fluid gearing, friction gearing, gearings with endless flexible members or other particular types of gearing
  • F16H61/02—Control functions within control units of change-speed- or reversing-gearings for conveying rotary motion ; Control of exclusively fluid gearing, friction gearing, gearings with endless flexible members or other particular types of gearing characterised by the signals used
  • F16H61/0202—Control functions within control units of change-speed- or reversing-gearings for conveying rotary motion ; Control of exclusively fluid gearing, friction gearing, gearings with endless flexible members or other particular types of gearing characterised by the signals used the signals being electric
  • F16H61/0251—Elements specially adapted for electric control units, e.g. valves for converting electrical signals to fluid signals
  • F16H2061/0258—Proportional solenoid valve

Definitions

• the invention relates to a proportional pressure control valve with a pressure reducing and a pressure maintaining function.
• the valve essentially consists of a valve housing with inlet and outlet openings, a control element for opening and closing the valve seat and / or throttle gap, an armature rod with an armature axis for connecting the control element to a proportional magnet, which consists of a magnetic core, a magnet armature and a magnetic coil.
• the magnet armature can be moved back and forth in the direction of the armature axis between two end positions, the first end position corresponding to a holding position of the magnet armature, ie. that is, the magnet armature keeps at least one valve seat closed by means of the control element.
• Valves of the type mentioned above are widely known from the prior art; they are used, for example, as pilot valves for actuating clutches in automatic motor vehicle gearboxes.
• the main hydraulic pressure, or system pressure is approximately 10 bar or more, for example in car transmissions.
• This main pressure is usually reduced by a pressure reducing valve to a pilot pressure of approx. 5 bar, which is also applied to the proportional pressure control valve.
• a safety excess pressure which corresponds approximately to the system pressure, is usually applied to the clutch cylinder and maintained by additional holding valves.
• three valves namely a proportional pressure control valve, a pressure reducing valve and one Pressure maintenance valve, for operation, for example a clutch in an automatic transmission, is required.
• the object of the present invention is to provide a valve which fulfills the above-mentioned functions and has a simpler structure, for example by fewer components, and is therefore less expensive to manufacture.
• this object is achieved in that with a proportional pressure control valve of the aforementioned type in the holding position of the magnet armature, the smallest axial distance between the two opposite ends of the magnet armature and the magnet core is dimensioned such that the magnetic force between the magnet armature and the magnet core in this holding position is greater than the magnetic force in the working area of the proportional magnet and that the magnet armature can be determined in this holding position by the excessive magnetic force.
• the invention takes advantage of the fact that a proportional magnet in its working area has an almost horizontal force-stroke characteristic and the magnetic force in a range below a certain stroke, ie a distance between the magnet armature and the magnetic core, compared to the magnetic force in Work area increases by leaps and bounds.
• the holding function according to the invention advantageously enables the blocking of vibratable masses in the pressure regulator; this is more vibration stable and is subject to less mechanical wear.
• control element has two control edges, which are designed as a flat seat and as a slide edge.
• a cost-effective design in particular a 3/2-way pressure regulator with a magnetic holding function of the magnet armature, can be specified in a simple manner, the flat seat being provided to fulfill the pressure holding function and the pressure regulator advantageously being used as a pilot control element.
• a spring element for example a helical compression spring, be arranged between the magnet armature and the anchor rod. This initially ensures that the anchor rod does not directly touch the magnet armature and that there is also a static indeterminacy between the flat Seat of the control and the end stop of the anchor rod on the anchor is compensated.
• the compression spring which is arranged between the armature rod and the magnet armature, advantageously has a “hard” spring characteristic, as a result of which the proportional range of the magnet is passed over, and the magnet armature is quickly switched from the working area to the holding position and the reinforcement is increased
• the spring force of the compression spring is advantageously chosen such that it is greater than or equal to the maximum hydraulic control force on the flat seat, which corresponds to the product of the maximum hydraulic control pressure times the nominal area of the flat seat the spring thus represents a "snap-through protection" in the hydraulic system.
• the spring rate of the compression spring is advantageously dimensioned as small as possible so that the magnet armature can be brought into the range of high magnetic forces even with a low coil current and the holding function of the magnet armature can thereby be realized; the magnet armature is "snapped" in this position.
• the compression spring is also designed with respect to its spring characteristic and its spring geometry, such as the spring length, the spring wire diameter, etc., and the fastening of the spring between the armature and the armature rod is selected so that in the holding position of the magnet armature the smallest axial distance between the magnetic core and the magnetic armature is in the range from 0 to approximately 0.3 mm, preferably approximately ⁇ 0.1 mm. at this distance, the magnetic force is sufficiently large compared to the magnetic force in the working area, so that the magnet armature is advantageously held in its end position even when the main hydraulic pressure is applied.
• a spacer disk made of a non-magnetic material can be arranged between the magnet core and the magnet armature.
• a spacer disc which prevents the magnetic armature from "magnetically sticking" to the magnetic core, advantageously makes it easy to adjust the magnetic force by varying the disc thickness.
• a non-magnetic coating can also be provided on the magnetic core and / or on the magnetic armature be, which ensures compliance with the axial distance between the magnetic core and the armature.
• the distance between the end faces of the magnetic core and the magnet armature is approximately 0.01 to 0.3 mm, but preferably approximately ⁇ 0.1 mm, since a sufficient magnetic holding force is already achieved at this distance.
• This maximum magnetic holding force must be greater than the hydraulic force due to the maximum hydraulic operating pressure over the entire operating range of the pressure control valve.
• the magnet coil be connected to an electrical control device which supplies a current pulse to the magnet coil at predefinable time intervals Maintains the holding position of the magnet armature. This ensures that the magnet armature maintains its holding position relative to the magnetic core and does not inadvertently “drop” from the holding position and thus advantageously the sealing seat of the control element remains reliably closed.
• the current pulse has a current which. is greater than the holding current of the magnet coil and is, for example, approximately 950 A and that the current pulse occurs at time intervals of, for example, approximately 20 ms, since this period is shorter than the period in which the magnet armature could fall out of its holding position.
• the solenoid coil In order to deliberately release the magnet armature from the holding position, the solenoid coil is acted upon by an electrical control signal, which occurs, for example, by reducing and then ramping up the control current (loop control) in the solenoid coil. This allows the anchor to be released in a particularly elegant manner in a simple manner.
• a deliberate release of the magnet armature from its holding position can take place by means of a pressure signal, which takes place, for example, as an increase in the main hydraulic pressure to a value above the holding pressure and the pressure increase acts, for example, on the flat seat of the control element.
• a movement of the armature rod advantageously also releases the magnet armature from the magnet core.
• the proportional pressure control valve according to the invention is advantageously used as a pilot valve.
• the valve is preferably designed as a 3/2-way proportional pressure control valve with a magnetic holding function of the magnet armature, so that when using the valve according to the invention, both a pressure reducing valve and a pressure holding valve are omitted.
• the proportional pressure control valve according to the invention can also be used as a direct control valve, the hydraulic system pressure being modulated by the proportional pressure control valve and then acting directly on a volume-boosting slide, which has no pressure ratio, for actuating a clutch in a motor vehicle transmission.
• the proportional pressure control valve according to the invention can thus be used both as a pilot control valve and as a direct control valve in a hydraulic arrangement with a damper with a two-stage characteristic curve.
• This damper is followed by a follow-up slide in the form of a pressure step-up slide or a volume-increasing slide to minimize the pressure drop during the transition from the holding area to the working area.
• FIG. 1 shows a 3/2-way proportional pressure control valve as a pilot valve with a magnetic holding function of the armature in closed-end
• FIG. 2 shows a proportional pressure control valve, similar to the illustration in FIG. 1, but with an alternative connection between armature rod and armature;
• FIG. 3 shows a characteristic curve of the pressure p over the coil current I for a valve according to the invention with a holding function in a schematic representation
• FIG. 6 shows an arrangement with a proportional pressure regulating valve, a two-stage damper and a volume reinforcement slide in a schematic representation
• Fig. 7 shows a two-stage damper in a sectional view
• 8 shows a characteristic curve of the damper force over the damper travel for a two-stage damper according to FIGS. 7 and
• Fig. 9 shows a characteristic of the pressure P and the coil current I over time t in a schematic representation.
• the pressure regulating valve 1 (FIG. 1) essentially consists of a valve housing 2 and a proportional magnet 3, the inlet and outlet openings 4, 5, 6 being arranged in the lower part of the valve housing 2.
• a control element 7 for opening and closing the valve seat 16 and slide edge 17 is connected to an anchor rod 8, which has an anchor axis 9 and wherein the anchor rod 8 is guided in a bushing 24 and one end of the anchor rod 8 projects into the interior of a magnet armature 11 .
• a disk 21 is attached to the end of the anchor rod 8. This end of the armature rod 8 with the disk 21 projects into an essentially cylindrical recess in the magnet armature 11.
• a helical compression spring 20 is arranged between the disk 21 and the bottom of the recess in the armature 11. A rigid connection between the armature rod 8 and the magnet armature 11 is thereby avoided.
• the magnet armature 11 is in its second end position, ie in the “upper” stop position, so that the distance 13 between the end face 14 of the magnet armature 11 and the end face 15 of the magnet core 10 is maximum.
• the distance 13 is approximately 0 to 0.3 mm, preferably approximately ⁇ 0.1 mm.
• the control element 7 is thus moved on the one hand into its first “lower” end position by the magnet armature 11 via the compression spring 20 and the disk 21.
• this holding position (not shown) the flat seat 16 is closed, so that the hydraulic pressure present at the inlet opening 4 is closed cannot reach the drain opening 6 via the three bores 18.
• Opening of the flat seat 16 can be achieved by reducing the control current of the magnet coil and thereby also reducing the magnetic holding force of the magnet armature 11 to such an extent that the magnet armature 11 of the magnetic core 10.
• the control current is then immediately ramped up again (loop control), so that the “pressure drop” when the armature drops does not occur in the fine-adjustment region 31
• the flat seat 16 can also be opened by increasing the main hydraulic pressure within the inlet opening 4 and the ring channel 18 so that the hydraulic force on the “lower” ring surface of the flat seat 16 is greater than the magnetic holding force which is the armature 11 on the magnetic core 10 holds.
• the proportional pressure control valve 1 can be connected to an electrical control device, not shown.
• the essential structural features of the valve shown here correspond to the embodiment according to FIG. 1, so that the same components are also identified with the same reference numerals in both FIGS. 1 and 2.
• the connection of the armature rod 8 to the magnet armature 11 is different.
• the magnet armature 11 is provided on its top with a cup-shaped part, the open top of which is encapsulated by a closure disk 30 which is fastened to the magnet armature 11, for example caulked with it.
• a disc 21 is accommodated, which serves as a support for a compression spring 20.
• the compression spring 20 is provided between this disk 21 and the closure disk 30.
• the electrical lead 28 connects the magnetic coil 12 to an electrical control device, not shown.
• Opening or "snapping back" of the solenoid valve can be achieved, for example, by applying a pressure increase, for example to the system pressure of approximately 13 bar, which acts on the flat seat of the control element and thereby lifts the magnet armature from the magnet core via the armature rod .
• Pressure control range from 0 to 12 bar; the measurements were carried out twice over a period of approx. 12 s.
• the residual air gap ie the minimum distance between the magnet armature and the magnet core, is approx. 0.1 mm.
• the pressure curve is very similar to the illustration in FIG. 3.
• the coil current increases, the pressure increases linearly above approx. 200 mA to approx. 6 bar. This is followed by a pressure jump from approx. 6 to approx. 10 bar with a "snap current" of approx. 950 mA.
• the coil current is first increased and then reduced.
• the valve pressure is in two Levels reduced to approx. 5 bar.
• the pressure p is then linearly reduced along a line parallel to the pressure increase.
• the course of the flow rate Q also follows a loop, but the course of the flow rate Q is different from that of the pressure curve p.
• the flow rate initially increases sharply to a maximum of approximately 1.6 l / min. If the coil current is increased further, the flow rate Q is gradually reduced to a value of approximately 0.2 l / min, which corresponds to a residual leakage of the flat seat. Due to the high magnetic holding force or contact pressure of the flat seat, this value is, according to the invention, very much lower than in series valves with a flat seat.
• the course of the flow rate Q when the coil current I is withdrawn is essentially parallel, but above the course for the flow rate Q when the current I is increased.
• a proportional magnet has an almost horizontal force-stroke characteristic in its working area Y_MA.
• the magnetic force F_MA is therefore essentially constant in the working area Y_MA.
• the magnetic force F_M decreases.
• the magnetic force F_M increases significantly.
• the magnetic force F_MH in the holding area has a significantly higher value than the magnetic force F_MA in the working area.
• the invention makes use of this fact by the magnet armature of the proportional magnet being attracted to the magnet core by a current increase in the magnet coil and thus produces a significant increase in the closing force at the flat seat of the valve.
• a hydraulic system pressure is generated in a hydraulic fluid by means of a pump 32. This is pumped through a filter 33 and an orifice plate 34 to an inlet opening 4 of the pressure control valve 1.
• the function of the valve 1 essentially corresponds to the illustration in FIG. 1.
• Via the working connection 5 of the pressure control valve 1, the latter is connected to a follow-up slide, for example a volume flow amplification slide 38.
• a two-stage damper 35 is arranged between the pressure control valve 1 and the follower slide 38.
• the slide 38 is connected to a clutch 37.
• the two-stage damper 35 is shown again in a schematic and enlarged representation in FIG. 7.
• the inflow to the damper 35 takes place from the pressure control valve 1; the sequence takes place to the follow-up slide or volume flow boost slide 38.
• the damper 35 essentially consists of a pot-shaped damper housing with an aperture bore 36. Inside the damper there is a compression spring 39 with a spring constant Cl and a second compression spring 40 with a spring constant
• the two springs 39 and 40 are matched to one another such that the spring 39 is first compressed with the spring constant C1 in the control range. After the transition from the control range to the holding range, the damping takes place by means of a combination of the two springs 39 and 40. If the damper force F_D runs over the damper travel S_D (FIG. 8), there is initially a linear increase in the control range according to the spring rate Cl up to the spring travel S_P_Regel_max, at which the maximum control pressure is reached. In the stopping area that follows, the total spring rate of the damper is summed up from the individual spring rates C1 and C2, it being possible for the slope of the characteristic curve to be made variable by any combination of the two spring rates.
• FIG. 9 The effects of the aforementioned two-stage damper on the pressure drop in a pressure control valve according to the invention are shown in FIG. 9.
• a linear increase in the coil current I initially results in a linear increase in the pressure p in the control pressure range at substantially the same time. Then there is a sudden increase in both the coil current I and the pressure p up to the system pressure. Until the course of the pressure drop, shown in enlarged form, is reached, the pressure p is kept approximately constant at the shark pressure level, while the coil current I also has current pulses, so-called refresh peaks, which are not shown for the sake of simplicity, in order to maintain the holding function.
• the current I is first reduced, as a result of which the pressure curve p also drops from its holding pressure to the pressure drop point 41.
• Coil current I the course of the pressure p is “caught” again and checked back into the control pressure range. hazards. This corresponds to a course with a conventional damper.
• the pressure drop is significantly reduced, so that the pressure curve p is already captured at a pressure drop point 42 above the control pressure range and can then be returned in a controlled manner to the control pressure range.

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• Physics & Mathematics (AREA)
• Engineering & Computer Science (AREA)
• Electromagnetism (AREA)
• Fluid Mechanics (AREA)
• General Physics & Mathematics (AREA)
• Automation & Control Theory (AREA)
• Power Engineering (AREA)
• Magnetically Actuated Valves (AREA)
• Electromagnets (AREA)
• Control Of Fluid Pressure (AREA)

Priority Applications (6)

Applications Claiming Priority (2)

Publications (1)

Family

ID=7896668

Family Applications (1)

Country Status (7)

Families Citing this family (59)

Citations (4)

Family Cites Families (14)

• 1999
  • 1999-02-06 DE DE19904901A patent/DE19904901A1/de not_active Withdrawn
• 2000
  • 2000-01-31 EP EP00910630A patent/EP1151219B1/de not_active Expired - Lifetime
  • 2000-01-31 US US09/890,169 patent/US6619615B1/en not_active Expired - Lifetime
  • 2000-01-31 DE DE50002168T patent/DE50002168D1/de not_active Expired - Lifetime
  • 2000-01-31 KR KR1020017009776A patent/KR20010101955A/ko not_active Application Discontinuation
  • 2000-01-31 AU AU32779/00A patent/AU3277900A/en not_active Abandoned
  • 2000-01-31 WO PCT/EP2000/000731 patent/WO2000046534A1/de not_active Application Discontinuation
  • 2000-01-31 JP JP2000597575A patent/JP4549539B2/ja not_active Expired - Fee Related

Patent Citations (4)

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